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Mon May 31, 2010 7:28 am

Can anybody reveal to me the secret of stopping a 36hp fuel pump from leaking oil? I've never been able to get mine completely dry. I've tried silicone , Gaska-Cinch, you name it. And yes, the fuel pump base is good - it's an NOS one, no cracks. It has never leaked at the case, always at the the pump base. I'm getting ready to install a beautifully rebuilt pump from Vintage Werks, but I'm still afraid! What do you folks do (if anything) in addition to the paper gaskets to keep things dry?

Mon May 31, 2010 10:36 am

There are quite a few paper gaskets out there.. I have notices some are as thin as a sheet of paper... and others are a little thicker and made of REAL gasket material... You want to start with the best gaskets you can... and then use Permatex 3H on every surface.... case, gaskets, pump block and pump.. nice light coating.. make sure you get all the thin edges of the pump really good.. dont worry about extra on the outside you can clean it up with a rag and alcohol (but dont get alcohol on the seam).. I do it that way everytime and no leaks.

Mon May 31, 2010 8:58 pm

There's a few topics that you can find on thesamba that talk about gasket sealers, search in the performance section, and you will find as many opinions there as on the 'which oil to use' topic. The fuel pump leaking isn't so much a problem with which gasket or sealer to use, as it is an inherent flaw in the fuel pump base. Over time, the pump base tends to warp between the mounting holes making a big gap. If you've purchased a rebuilt pump from a respectable builder, they have already planed the pump base flat, but check it on a flat surface just to make sure.

Thu Jun 03, 2010 4:30 pm

The different thicknesses in gaskets are intentional. You use a thicker one to decrease fuel pump pressure or a thinner one to increase as needed.

Thu Jun 03, 2010 5:09 pm

duginabug wrote: The different thicknesses in gaskets are intentional. You use a thicker one to decrease fuel pump pressure or a thinner one to increase as needed.

Maybe if they are all from 1 manufacturer.. but from 6 different manufacturers? total different materials... it has alot to do with the age of the kits also.... Older kits seem to have thicker better gaskets.

Thu Jun 03, 2010 10:32 pm

duginabug wrote: The different thicknesses in gaskets are intentional. You use a thicker one to decrease fuel pump pressure or a thinner one to increase as needed.

He is right! If you plane a fuel pump base flat again, You will need to make up the removed material with extra gaskets.
I rebuilt a 36hp pump myself and flat surfaced all the gasket mating surfaces. I installed it and the carb immediately flooded over. I thought I had some junk get into the needle and seat. Well after about the third try, I contacted an old VW Head and he told me all about it. Added another gasket and WAH-LAH....
It was hard to believe that one extra gasket lowered the fuel pressure from over 5psi to about 2psi, but it did!

Fri Jun 04, 2010 6:17 am

Thanks for the replies gang. Yes, the pump base was planed, and on a trial installation I found that I needed 2 paper gaskets for the proper pressure. I ordered a tube of Hylomar Aerograde gasket sealer, which numerous sources have told me , is the last word. Hopefully, this will do it...

Fri Jun 04, 2010 8:35 pm

Early '54 (to mid-August) fuel pumps are lubricated by crankcase oil; late '54-on are lubricated by grease. If you are running a later 36hp fuel pump without the big drain screw, you need to swap the early bakelite base with the big oil hole for a later base without the hole. The later 36hp fuel pumps are not designed to be lubricated by crankcase oil and will leak.

However, the early fuel pumps can be lubricated by either oil or grease--VW continued to install the early-style fuel pumps well into 1955 before dropping the drain screw.

Sat Jun 05, 2010 5:42 am

Janerick3 - this is VERY interesting. I never knew of these details. I had been running a 36 hp pump with the brass screw on top to access the internal filter. I recently acquired the correct pump for my car (without the screw). So, I guess I had been running a "later" 36 and now I have an "early". Could you please elaborate a bit on what the "big drain screw" and the "big oil hole" are and where they're located? Details please, and thanks!!

Sat Jun 05, 2010 5:49 am

i never noticed a difference between the 8.29 numbered bases and the 9 digit numbered bases like janerick3 mentions. i will have to check that out later today.
here are pics of fuel pumps, you can see the earlier ones have screws on the bases.

Top Row, left to right: 8mm inlet & outlet, smooth top. 6mm inlet & outlet, smooth top. 6mm inlet & outlet, "domed" top, short outlet, with wavy screw area.
Bottom Row, left to right: 6mm inlet & outlet, "domed" top, short outlet, reinforcement ribbed top. 6mm inlet & outlet, domed top, tall outlet, reinforcement ribbed top. 6mm inlet & outlet, inline filter, tall outlet, reinforcement ribbed top.

Sat Jun 05, 2010 10:55 pm

I'd be interested in seeing the early fuel pump base with the large oiling hole as I don't believe I have one here.

Sun Jun 06, 2010 2:40 am

The oil hole was on the intermediate flange, not on the fuel pump itself.
It was deleted 19 Aug 54, on chassis 1 - 0 696 205. (P.R. p. M23)

I believe that the top right fuel pump in the photos is a late 55 only pump - with the boss for the lower screw but no screw. I have only ever seen in on 56 year models built in 1955. I'd be interested to know if any 55 year models or 56 built engines had it??

Sun Jun 06, 2010 8:03 am

Volumex wrote: The oil hole was on the intermediate flange, not on the fuel pump itself.
It was deleted 19 Aug 54, on chassis 1 - 0 696 205. (P.R. p. M23)

I believe that the top right fuel pump in the photos is a late 55 only pump - with the boss for the lower screw but no screw. I have only ever seen in on 56 year models built in 1955. I'd be interested to know if any 55 year models or 56 built engines had it??

P.R. (page K-7) lists the introduction of a "beaded cover plate" on 15 Feb 1956, at Engine No. 1326994. Perhaps this was when the fuel pump with the ribbed cover and no boss for the drain screw was introduced (lower left in the above pictures).

For what it's worth, I think DVG started a new series of serial numbers with this redesign.

Sun Jul 03, 2011 6:13 pm

What about oil leaking out of the "weep hole" on the under side of the fuel pump? ? I have been told too much crankcase pressure can cause it, but that seems normal. Is on a WW Okrasa style kit motor. Can really spray the engine with oil under long highway runs. Took fuel pump off and repacked with grease, blew out push rod pass thru. Everything looks good with Vintage Werks refurbished pump but still leaks out weep hole.

Any ideas?

Thanks

Mon Jul 04, 2011 3:02 am

Probably too much crankcase pressure IMO or too much pushrod bore play? Try another spacer, it may work. That much engine oil is not supposed to travel that far.
Are you sure it's not liquified grease that comes out the vent hole?
Try high boiling point grease instead.

Is this what you want to see Everett?

Mon Jul 04, 2011 6:45 am

Frank Ram, I have exactly the same oil weeping from the pump litle breathing hole....
I also have the WW Okrasa Kit in there and I've tried to change for a thicker grease, a super clean bakelite spacer (mine have the oil hole for the pushrod lubrication), a super smooth pushrod....without sucess.

Although, the only thing that seems to help is to add some paper spacer gaskets in order to reduce the pump pushrod travel. Doing this has a "risky side" that is to starv the carbs....
I have done some tests, trying to found the rigth (minimum) amount of spacers that not cause fuel starvation. I think that I've found it and the oil weeping is now just a thiny one that I only must clean every other day or less.

Janerick3. Do you mean that the later 36 Hp bakelite spacers does not have the lubrication hole ? Have you experience in using one without the hole ? If you right I must found one without it....maybe this is the cause.

Mon Jul 04, 2011 7:22 am

So how may paper seals did you end up with?
I wonder if this is common with the WW Okrasa Kit. It is not much more than a trickle for short trips around town. But, a long road trip on a hot day up and down hills can spell - oil everywhere. I suppose I could look for another spacer and use different grease but it sounds like that has already been tried. Any other ideas?

Thanks for the input. Please keep it coming.

Mon Jul 04, 2011 8:45 am

I have 4 or 5 spacers (about 5 mm.) there. But this depends on several things like if the pushrod lenght is stock, if the pump surface is warped or not, the diaphragm strentght, the fuel pressure you need etc.
So do not take that number as your number. You must find it with your own pump and carbs.

I suggest that besides that, try to find another spacer and pushrod and experiment. That is what I am going to do because I am not happy with the tiny weep.

https://www.thesamba.com/vw/gallery/pix/825076.jpg

Maybe this photo is more helpfull. It refers to the distance between the pump and a specific spot on the case (mine).

Mon Jul 04, 2011 11:07 am

OK Flavio, I'm with you. I will do the same and let you know.

Much thanks,
FR

Mon Jul 04, 2011 1:27 pm

piet&som wrote: Probably too much crankcase pressure IMO or too much pushrod bore play? Try another spacer, it may work. That much engine oil is not supposed to travel that far.
Are you sure it's not liquified grease that comes out the vent hole?
Try high boiling point grease instead.

Is this what you want to see Everett?

This is the early spacer (P/N 08.29). The post Aug '54 spacer (111.127.303) does not have this hole. If you use the 08.29 spacer with a later fuel pump designed for grease lubrication, you will get oil leaks from the weep hole.